Geraldton–Greenstone Weather Forecast – From Chilly Start to Sunny Spark
Cold Dawn, Warm Finish — Spring’s Mood Swings Continue
Geraldton & Greenstone, ON – Wednesday, May 21, 2025: The day begins on a frosty note in Geraldton and across Greenstone, where it’s a crisp 0.0°C at 6:00 AM at Geraldton Airport. With clear sunny skies, the beauty belies the chill — and with a northeast wind at 11 km/h, it feels closer to -4°C thanks to the wind chill. Humidity is quite high at 82%, which will make the air feel damp before the sun fully warms things up. The barometric pressure is a strong 102.3 kPa, a sign of generally stable conditions — for now.
Expect a mix of sun and cloud throughout the day, with that brisk northeast wind increasing to 20 km/h and gusting up to 40 km/h. Despite the frigid start, the temperature will rise sharply to a pleasant high of 15°C, giving us a rare Northern Ontario “spring jackpot” day. And with a UV index of 7, it’s definitely a day for sunscreen — even if you’re still scraping frost off the car this morning.
Showers Set to Sneak In Overnight
Tonight, things take a turn as clouds roll in and a 40% chance of showers develops overnight. Winds will stay active from the northeast at 20 km/h with gusts to 40 km/h, becoming lighter later in the evening before shifting to the north at 20 km/h after midnight. The overnight low will dip to +2°C, so we’re not done with the chilly air just yet.
Cooler, Wetter Weather Through Thursday and Friday
Thursday will be cloudy with a 40% chance of morning showers, and quite a bit cooler than today. The high will only reach 6°C, with a persistent north wind at 20 km/h keeping the day feeling colder than it is. The UV index drops to 2, so sunshine will take a back seat. Thursday night stays cloudy with a 40% chance of additional showers, and another low of +2°C.
Friday follows suit with cloudy skies and a 60% chance of showers, and the high creeping up to 11°C. The pattern continues Friday night, with cloudy periods and a 30% chance of showers. Overnight temperatures hover near +1°C.
What to Wear?
Mornings like this call for a warm coat and gloves, especially with the wind chill near -4°C. As the day warms to a spring-like 15°C, layers will keep you comfortable. Sunglasses and sunscreen are essential for midday, while an umbrella and waterproof gear will be handy for tonight and the coming days.
Historic Temperatures for May 21
Historically, Geraldton has seen a record high of 29.5°C on this date — a reminder of the swing potential in spring weather. The record low was a chilly -6.0°C, so while we’re waking up to zero, it could be worse… and has been!
Greenstone Weather Trivia
Did you know Geraldton is one of Ontario’s frostiest towns during the transitional seasons? Thanks to its elevation and northern location, spring frosts can sneak in well into late May — so if your tomatoes aren’t planted yet, they’re probably better off waiting a few more days!
